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Lrp, a global regulator, regulates the virulence of Vibrio vulnificus
BACKGROUND: An attenuated mutant (designated NY303) of Vibrio vulnificus, which causes serious wound infection and septicemia in humans, was isolated fortuitously from a clinical strain YJ016. This mutant was defective in cytotoxicity, migration on soft agar and virulence in the mouse. The purpose o...
Autores principales: | , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5554404/ https://www.ncbi.nlm.nih.gov/pubmed/28800764 http://dx.doi.org/10.1186/s12929-017-0361-9 |
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author | Ho, Yu-Chi Hung, Feng-Ru Weng, Chao-Hui Li, Wei-Ting Chuang, Tzu-Hung Liu, Tsung-Lin Lin, Ching-Yuan Lo, Chien-Jung Chen, Chun-Liang Chen, Jen-Wei Hashimoto, Masayuki Hor, Lien-I |
author_facet | Ho, Yu-Chi Hung, Feng-Ru Weng, Chao-Hui Li, Wei-Ting Chuang, Tzu-Hung Liu, Tsung-Lin Lin, Ching-Yuan Lo, Chien-Jung Chen, Chun-Liang Chen, Jen-Wei Hashimoto, Masayuki Hor, Lien-I |
author_sort | Ho, Yu-Chi |
collection | PubMed |
description | BACKGROUND: An attenuated mutant (designated NY303) of Vibrio vulnificus, which causes serious wound infection and septicemia in humans, was isolated fortuitously from a clinical strain YJ016. This mutant was defective in cytotoxicity, migration on soft agar and virulence in the mouse. The purpose of this study was to map the mutation in this attenuated mutant and further explore how the gene thus identified is involved in virulence. METHODS: The whole genome sequence of mutant NY303 determined by next-generation sequencing was compared with that of strain YJ016 to map the mutations. By isolating and characterizing the specific gene-knockout mutants, the gene associated with the phenotype of mutant NY303 was identified. This gene encodes a global regulator, Lrp. A mutant, YH01, deficient in Lrp was isolated and examined in vitro, in vivo and ex vivo to find the affected virulence mechanisms. The target genes of Lrp were further identified by comparing the transcriptomes, which were determined by RNA-seq, of strain YJ016 and mutant YH01. The promoters bound by Lrp were identified by genome footprinting-sequencing, and those related with virulence were further examined by electrophoretic mobility shift assay. RESULTS: A mutation in lrp was shown to be associated with the reduced cytotoxicity, chemotaxis and virulence of mutant NY303. Mutant YH01 exhibited a phenotype resembling that of mutant NY303, and was defective in colonization in the mouse and growth in mouse serum, but not the antiphagocytosis ability. 596 and 95 genes were down- and up-regulated, respectively, in mutant YH01. Many of the genes involved in secretion of the MARTX cytotoxin, chemotaxis and iron-acquisition were down-regulated in mutant YH01. The lrp gene, which was shown to be negatively autoregulated, and 7 down-regulated virulence-associated genes were bound by Lrp in their promoters. A 14-bp consensus sequence, mkCrTTkwAyTsTG, putatively recognized by Lrp was identified in the promoters of these genes. CONCLUSIONS: Lrp is a global regulator involved in regulation of cytotoxicity, chemotaxis and iron-acquisition in V. vulnificus. Down-regulation of many of the genes associated with these properties may be responsible, at least partly, for loss of virulence in mutant NY303. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12929-017-0361-9) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-5554404 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-55544042017-08-15 Lrp, a global regulator, regulates the virulence of Vibrio vulnificus Ho, Yu-Chi Hung, Feng-Ru Weng, Chao-Hui Li, Wei-Ting Chuang, Tzu-Hung Liu, Tsung-Lin Lin, Ching-Yuan Lo, Chien-Jung Chen, Chun-Liang Chen, Jen-Wei Hashimoto, Masayuki Hor, Lien-I J Biomed Sci Research BACKGROUND: An attenuated mutant (designated NY303) of Vibrio vulnificus, which causes serious wound infection and septicemia in humans, was isolated fortuitously from a clinical strain YJ016. This mutant was defective in cytotoxicity, migration on soft agar and virulence in the mouse. The purpose of this study was to map the mutation in this attenuated mutant and further explore how the gene thus identified is involved in virulence. METHODS: The whole genome sequence of mutant NY303 determined by next-generation sequencing was compared with that of strain YJ016 to map the mutations. By isolating and characterizing the specific gene-knockout mutants, the gene associated with the phenotype of mutant NY303 was identified. This gene encodes a global regulator, Lrp. A mutant, YH01, deficient in Lrp was isolated and examined in vitro, in vivo and ex vivo to find the affected virulence mechanisms. The target genes of Lrp were further identified by comparing the transcriptomes, which were determined by RNA-seq, of strain YJ016 and mutant YH01. The promoters bound by Lrp were identified by genome footprinting-sequencing, and those related with virulence were further examined by electrophoretic mobility shift assay. RESULTS: A mutation in lrp was shown to be associated with the reduced cytotoxicity, chemotaxis and virulence of mutant NY303. Mutant YH01 exhibited a phenotype resembling that of mutant NY303, and was defective in colonization in the mouse and growth in mouse serum, but not the antiphagocytosis ability. 596 and 95 genes were down- and up-regulated, respectively, in mutant YH01. Many of the genes involved in secretion of the MARTX cytotoxin, chemotaxis and iron-acquisition were down-regulated in mutant YH01. The lrp gene, which was shown to be negatively autoregulated, and 7 down-regulated virulence-associated genes were bound by Lrp in their promoters. A 14-bp consensus sequence, mkCrTTkwAyTsTG, putatively recognized by Lrp was identified in the promoters of these genes. CONCLUSIONS: Lrp is a global regulator involved in regulation of cytotoxicity, chemotaxis and iron-acquisition in V. vulnificus. Down-regulation of many of the genes associated with these properties may be responsible, at least partly, for loss of virulence in mutant NY303. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12929-017-0361-9) contains supplementary material, which is available to authorized users. BioMed Central 2017-08-11 /pmc/articles/PMC5554404/ /pubmed/28800764 http://dx.doi.org/10.1186/s12929-017-0361-9 Text en © The Author(s). 2017 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Ho, Yu-Chi Hung, Feng-Ru Weng, Chao-Hui Li, Wei-Ting Chuang, Tzu-Hung Liu, Tsung-Lin Lin, Ching-Yuan Lo, Chien-Jung Chen, Chun-Liang Chen, Jen-Wei Hashimoto, Masayuki Hor, Lien-I Lrp, a global regulator, regulates the virulence of Vibrio vulnificus |
title | Lrp, a global regulator, regulates the virulence of Vibrio vulnificus |
title_full | Lrp, a global regulator, regulates the virulence of Vibrio vulnificus |
title_fullStr | Lrp, a global regulator, regulates the virulence of Vibrio vulnificus |
title_full_unstemmed | Lrp, a global regulator, regulates the virulence of Vibrio vulnificus |
title_short | Lrp, a global regulator, regulates the virulence of Vibrio vulnificus |
title_sort | lrp, a global regulator, regulates the virulence of vibrio vulnificus |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5554404/ https://www.ncbi.nlm.nih.gov/pubmed/28800764 http://dx.doi.org/10.1186/s12929-017-0361-9 |
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